Tuning Magnetic Anisotropy Energy of Femirn(M+N=3) by Crystalline Field between Cluster and Mgo Substrate

Abstract

Abstract: Nanomagnetic materials have been extensively researched in recent years with the miniaturization at magnetic storage size scales. Here we explored structural and magnetic properties of free FemIrn  clusters and MgO supported FemIrn (FemIrn @MgO(m+n+3)) using density functional theory(DFT) calculations. Our results indicate that the magnetic anisotropy energy (MAE) of FemIrn (m+n=3) gradually increases with the addition of Ir atoms due to the spin-orbit coupling effect. The perpendicular MAE of FeIr2 reaches 23.06 meV due to the coupling of the occupied degenerate dx2y2/xy orbital and unoccupied dxy orbital. Furthermore, the MgO substrate can change the magnitude of MAE and easy magnetized direction of free clusters. In particular, the MAE of FeIr2@MgO can be controlled by the distance between FeIr2 cluster and MgO substrate and reaches large perpendicular magnetic anisotropy of 15.18meV at h=3.03Å. Meanwhile, the MgO substrate induces the easily magnetized axis of Ir3 cluster change from in-plane to out-plane, which is attributed to the change of d orbitals near Fermi level energy.

Keywords: MgO substrate/ clusters / Magnetic anisotropy energy/ DFT